This invention relates generally to hand held laser apparatuses and more particularly to hand held laser apparatuses for directly delivering a high power output in either a continuous wave or a pulsed mode of operation to a workpiece by means of a lens assembly or a combination of a lens assembly and fiber optic assembly.
In many applications, such as the medical field and industrial processing, it is desirable to position and direct a beam of laser light to a target through the manipulation of a hand held device. By utilizing a hand held device the operator may obtain a more precise location of the laser light and be able to rapidly alter its position as conditions warrant. Typically, large laser generators, such as a Nd:YAG laser generator or a CO.sub.2 laser generator, have been utilized wherein these relatively large laser generators are coupled to a mobile hand piece by means of fiber optic cabling. Thus, by correctly orientating the hand piece, the light generated by the laser generator could be applied to the workpiece. The use of such large laser generators, however, suffered from several deficiencies. One such deficiency is the need to house and maintain the relatively large laser generator as well as the requirement that it is positioned within a fairly short distance from the sight of the laser's utilization due to the desire to minimize problems with the fiber optic coupling. Additionally, such laser generators performed relatively inefficiently in comparison to modern semiconductor laser diodes.
It is also desirable that such hand held laser apparatuses be able to provide both continuous wave and pulsed modes of operation since the various applications to which the hand held laser apparatuses could be applied may required varying operating characteristics by the laser. For example, in the medical field the various applications of the hand held laser apparatus such as photocoagulation, tissue welding, photodynamic therapy, contact surgery and tissue ablation each typically require different operating characteristics by the laser in order to most efficiently perform the desired medical function. Additionally, for a hand held laser apparatus operating in a pulsed mode, it would be desirable that the pulsewidth as well as the repetition rate of the pulses be variable so as to optimize the laser's pulses for the application to which it is applied.
Additionally, for a hand held laser apparatus wherein the laser diode itself is contained within the hand held apparatus, it would be desirable for the output of the laser diode to be directed upon the workpiece without the need for fiber optic coupling. By applying the laser beam directly to the workpiece without the use of fiber optic coupling, problems inherent in the use of coupling the laser output to the fiber optic cable in its transmission therethrough are avoided. Furthermore, it is desirable to have the power level of the hand held laser device be variable to accommodate various applications of the apparatus as well as providing a means detecting the output power so that manual adjustment could be made in the case of an errant power output.